Atm Qos; Traffic Shaping - ZyXEL Communications IES-1000 User Manual

LABEL
Edit Port Setup
Port Setup
VPI/VCI
Active
PVID
Priority
VC Profile
Add
Delete
13.3

ATM QoS

ATM Quality of Service (QoS) mechanisms provide the best service on a per-flow guarantee. ATM network
infrastructure was designed to provide QoS. It uses fixed cell sizes and built-in traffic management (see the
following section on traffic shaping). This allows you to fine-tune the levels of services on the priority of the
traffic flow.
13.4

Traffic Shaping

Traffic shaping is an agreement between the carrier and the subscriber to regulate the average rate and fluctuations
of data transmission over an ATM network. This agreement helps eliminate congestion, which is important for
transmission of real time data such as audio and video connections.
13.4.1 ATM Traffic Classes
These are the basic ATM traffic classes defined by the ATM Forum Traffic Management 4.0 Specification.
Constant Bit Rate (CBR)
Constant Bit Rate (CBR) is an ATM traffic class that provides fixed bandwidth. CBR traffic is generally time-
sensitive (doesn't tolerate delay). CBR is used for connections that continuously require a specific amount of
bandwidth. Examples of connections that need CBR would be high-resolution video and voice.
Virtual Channel Management
Table 13-1 DSL Port Channel Setup
Click this link to go to the Edit Port Setup screen.
Click this link to go to the Port Setup screen.
This field displays the Virtual Path Identifier (VPI) and Virtual Circuit Identifier (VCI). The
VPI and VCI identify a channel on this port.
Click a link in the VPI/VCI column to open a screen where you can edit the VPI/VCI
settings.
This field shows whether the channel is turned on (Yes) or not (No).
This is the PVID (Port VLAN ID) assigned to untagged frames or priority frames (0 VID)
received on this channel. An asterisks (*) denotes a super channel.
Type the priority value (0 to 7) to add to incoming frames without a (IEEE 802.1p) priority
tag. An asterisks (*) denotes a super channel.
This shows which VC profile the channel is set to use.
Click this button to configure a new channel.
Select a channel's Delete check box and click the Delete button to remove the channel.
DESCRIPTION
IES-1000 User's Guide
13-3